Azonitriles are produced by a process described by Anderson in U.S. Pat. No. 2,711,405 which involves reacting the cyanohydrin of an aliphatic ketone with ammonia to form an aminonitrile and oxidatively coupling the aminonitrile to form the azo using an alkali metal or alkaline earth metal hypochlorite in aqueous medium. De Benneville in U.S. Pat. No. 2,713,576 claimed essentially the same process with the addition of alkyl hypochlorites and restriction of aminonitriles to those of acetone, methyl ethyl ketone and diethyl ketone. A process improvement which enables azonitriles to be prepared from aminonitriles of higher molecular weight ketones in good yields is reported by Fuchs in U.S. Pat. No. 3,783,148. Methanol or ethanol is employed as a reaction solvent in proportion to the amounts of aminonitrile and hypochlorite solution used such that, at the completion of the reaction, the alcohol concentration is at least 70% by volume. The alcohol maintains a homogeneous system throughout the reaction and specifically prevents separation of the intermediate, highly hydrophobic chloramines.
U.S. Pat. No. 4,028,345 discloses a process which does not involve the alcohol solvent with all its drawbacks by coupling alpha-aminonitriles in the presence of a metal hypochlorite, water and a surface active compound to form aliphatic azodinitriles.
U.S. Pat. No. 4,051,124 discloses a process for preparing 2,2'-azobis(2-methylpropanenitrile) by coupling 2-amino-2-methylpropanenitrile in the presence of a metal hypochlorite, water and a mixture of a quaternary ammonium compound and a nonionic or amphoteric surface active compound. The 2,2'-azobis (2-methylbutanenitrile) produced by the aforesaid process does not have the quality desired.